rs72558468

Variant names:

• chrX-38411925-G-A
• rs72558468
• NM_000531.6:c.931G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000531.6(OTC):​c.931G>A​(p.Val311Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000913 in 1,095,848 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. V311V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: OTC NM_000531.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 9.43
• Publications: 6 publications found

Genes affected

OTC (HGNC:8512): (ornithine transcarbamylase) This nuclear gene encodes a mitochondrial matrix enzyme. The encoded protein is involved in the urea cycle which functions to detoxify ammonia into urea for excretion. Mutations in this enzyme lead to ornithine transcarbamylase deficiency, which causes hyperammonemia. [provided by RefSeq, May 2022]

OTC Gene-Disease associations (from GenCC):

• ornithine carbamoyltransferase deficiency

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, G2P, Laboratory for Molecular Medicine, Orphanet

ENSG00000250349 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 17 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 uncertain in NM_000531.6
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 266 curated pathogenic missense variants (we use a threshold of 10). The gene has 15 curated benign missense variants. Gene score misZ: 1.3274 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to ornithine carbamoyltransferase deficiency.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
OTC	NM_000531.6	c.931G>A	p.Val311Met	missense_variant	Exon 9 of 10	ENST00000039007.5	NP_000522.3
OTC	NM_001407092.1	c.931G>A	p.Val311Met	missense_variant	Exon 11 of 12		NP_001394021.1
OTC	XM_017029556.2	c.*64G>A		downstream_gene_variant			XP_016885045.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
OTC	ENST00000039007.5	c.931G>A	p.Val311Met	missense_variant	Exon 9 of 10	1	NM_000531.6	ENSP00000039007.4
ENSG00000250349	ENST00000465127.1	c.172-254196G>A		intron_variant	Intron 3 of 8	5		ENSP00000417050.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome AF: 9.13e-7 AC: 1 AN: 1095848 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 361234

African (AFR) AF: 0.00 AC: 0 AN: 26348

American (AMR) AF: 0.00 AC: 0 AN: 35202

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19360

East Asian (EAS) AF: 0.00 AC: 0 AN: 30189

South Asian (SAS) AF: 0.00 AC: 0 AN: 54097

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40513

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4132

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 839971

Other (OTH) AF: 0.00 AC: 0 AN: 46036

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

-

GenMed Metabolism Lab

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Ornithine carbamoyltransferase deficiency Uncertain:1

Jul 09, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.6	H
PhyloP100		9.4
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-2.8	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.91
MutPred		0.91		Gain of disorder (P = 0.1153);
MVP		1.0
MPC		1.2
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.97
gMVP		0.96
Mutation Taster		=13/87	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs72558468; hg19: chrX-38271178;